class A2 {
  final double PI=3.1415926;
  public double getArea(final double r) {
    return PI*r*r;
  }
  public final void speak() {
    System.out.println("您好，How's everthing here?");
  }
}
public class Example5_9 {
  public static void main (String args[]){
    A2 a=new A2();
    System.out.println("面积："+a.getArea(100));
    a.speak();
  }
}
